Pneumatic System Schematic Circuit Diagram Information Technology Essay

Robot is a programmable, multifunction manipulator designed to move materials, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks (Regh, 2000). Robots consist of four basic components: (a) the manipulator, (b) the controller, (c) the power supply, and (d) the end-of-arm tooling. The manipulator is the arm of the robot. Robots have a wrist attached to the end of the arm. The wrist provides angular orientation of the work piece as the arm positions the wrist in space. The controller performs the complex computations for control of the robots joints to the proper position and velocity so that the end of the arm follows the assigned path at the assigned speed. It monitors the feedback signals from the robot’s joints and actuators. The power supply may be hydraulic, electric, or pneumatic depending on the robot. The end-of-arm tooling is attached to the robot wrist and consists of a device that is application specific. This can be a gripper to close around parts, a tool holder for a welding head, an automatic screwdriver and many other applications (RobotWorx, 1989).

PHD Parts Handlers are designed with flexibility of sequence and the variety of options and accessories which makes the Parts Handler ideal for various activities like material transfer, pick and place, turnover, load, unload, assembly and other repetitive motion requirements. The Parts Handler is a solution to repetitive motions associated with machine tools, die cast machines, injection molding manchines, packaing machines, spot welding machines, material handling systems and many other related industrial manchines (PHD, 2009).

The Pneumatic robot PHD Parts Handler needs to be interfaced to a PLC system and suitable PLC programming need to be done in order to configure the robot to do multiple programs that make the students aware of the robot usage.

PHD Parts Handler Y-4901 Features

Figure 2. PHD Parts Handler Y-4901 Features (PHD, Inc., 2009)

The general features and parts of the PHD Parts Handler are shown in Figure 2 and are as follows:

Motion – Rotary motion is converted to two axis harmonic linear motions through cranks and mechanical linkages.

Power – Pneumatic PHD rack and pinion rotary actuators provide power to linkages.

Slides – Precision case hardened shafts and linear ball bushing are incorporated in the unit.

Stroke Adjustment – Strokes are infinitely adjustable, within the stroke limitations, by adjusting the mechanical linkages.

Limit Switches – These are provided to signal the completion of slide stroke.

Speed Control – Flow controls are included on rotary actuators to enable speed control in each direction.

Manifold Block – This is a pneumatic header provided for internal port connections.

Fixture Plate – This plate may be used to mount gripping units and actuators.

Base – Cast aluminum base for easy mounting of parts handler. (Bole, 2009)

Pneumatic System

Pneumatics is that branch of technology, which deals with the study and application of use of pressurized gas to impinge mechanical motion. Pneumatic power is used in industry, where factory machines are commonly plumbed for compressed air; other compressed inert gases can also be used. Pneumatics also has applications in dentistry, construction, mining, and other areas. In the pneumatic system the energy is transferred by gas under pressure. The pneumatic actuators can be classified as either linear or rotary. The positions for linear devices are retracted and extended rotary actuators come to rest at the full clockwise rotation and the full counterclockwise position. The gas serves to force the movable part of the actuator against the block; robot tool position is established by the block setting. The advantages of using pneumatic power sources are that the compressed air is available in most manufacturing areas, and is generally inexpensive in comparison to other power sources (Regh, 2000).The pneumatic control schematic in Figure 1 shows different components of a pneumatic control system. The pneumatic pressure through the cylinders, that drives the rotary actuator links, is controlled using the solenoid valves. The valves have two ports and provide on-off control to the pneumatic system. The operation of the cylinder is controlled by using the flow control valves which restrict the airflow through the cylinders (Bole, 2009). Pneumatic logic systems also called air logic control are often used to control industrial processes, consisting of primary logic units.

Figure 3. Pneumatic System Schematic Circuit Diagram

The electrical wiring connections between the PLC and solenoid valves connect the PLC to the pneumatic control circuit.

Chapter 2

MicroLogix 1200

The MicroLogix 1200 is a PLC which comes from the AllenBradley MicroLogix family of micro controllers. It serves functionality between the MicroLogix 1000 and 1500. It has wide range of features and options which enables it to handle extensive applications.

Hardware Description

Figure 4: Hardware features of the Controller

Item

Description

Item

Description

1

Terminal Blocks

7

Terminal Doors and label

2

Bus Connector Interface to Expansion I/O

8

Trim Pots

3

Input LEDs

9

Default Communications Push Button

4

Output LEDs

10

Memory Module Port Cover

5

Communication Port IChannel

11

DIN Rail Latches

6

Status LEDs

12

Programmer HMIPort

The MicroLogix 1200 programmable controller can be connected to the personal computer using the DF1 protocol: using a point-to-point connection, or using a modem. In point-to-point connection method the programmable controller is connected to personal computer using a serial cable (1761-CBL-PM02) from the personal computer’s serial port to the controller via Channel 0 and/or the Programmer/HMI Port (MicroLogix 1200 Programmable Controllers, 2009).

Figure 5. Interface between MicroLogix 1200 and Personal Computer

MicroLogix 1200 programmable controller is programmed using RSLogix 500.

MicroLogix 1200 Installation

Most applications require installation of the controller in an industrial enclosure far from

Power lines, load lines, and other sources of electrical noise to reduce the effects of electrical interference. Isolation transformer can be used in the ac line to the controller to reduce the electrical noise that enters the controller and is often used as a step-down transformer to reduce line voltage. Vertical mounting is not recommended due to heat considerations. The controller is mounted horizontally, with the expansion I/O extending to the right of the controller. The memory module is installed into the controller as shown in figure 6.

Figure 6. Memory module installation

CHAPTER 3

RSLogix 500

RSLogix 500 software is a 32-bit Windows ladder logic programming package for the MicroLogix processors. It is compatible with SLC 500 and MicroLogix programs created with any of Rockwell Software’s programming packages.

Benefits of RSLogix 500

RSLogix programming packages make program maintenance across hardware platforms convenient and easy. In addition, RSLogix 500 benefits include:

Ladder

A free-form ladder editor concentrates on the application logic instead of syntax. Edit several rungs simultaneously using the Program Editor. Correct errors using the Project Verifier.

Drag-and-Drop Editing

It helps in quickly moving data table elements from one data file to another, rungs from one subroutine or project to another, or instructions from rung to rung within a project.

Diagnostics

Locate problem areas in the application using Advanced Diagnostics. It is easy to locate and replace addresses and description text easily using Search and Replace.

Compatibility

RSLogix provides compatibility with Rockwell Software’s popular MS-DOS programming products. It’s easy to migrate an existing project created in any of Rockwell Software’s previous programming products to RSLogix. (Rockwell Software, 2010)

Exploring RSLogix 500

To navigate through the various windows and toolbars in RSLogix 500 more easily, it’s important to know what functionality each provides.

Figure 7. RSLogix 500 software view

Menu bar: Select functionality from the menus that appear as one click’s each selection on this bar.

Icon bar: The icon bar contains many functions that can be used repeatedly to develop and test logic program.

Online bar: Shows processor mode, online edits, forces present, the communications driver and node number.

Project tree: This view contains all the folders and files contained in the project. It also provides selection like rename the program file, open the program file, hide the program file, or reveal properties of the program file.

Status bar: This view gives the ongoing status information

Results pane: Displays the results of a Find All search or a verification procedure. This pane can be hidden or placed anywhere on screen.

Ladder view: Ladder logic program is edited here. Several program files can be viewed at the same time.

Instruction toolbar: Displays instruction mnemonics in tabbed categories. When clicked on a category tab the instruction toolbar changes to show that category of instructions. Click an instruction to insert it in the ladder program.

System requirements

To use RSLogix 500 effectively, the personal computer must meet the following hardware and software requirements:

Hardware requirements

an Intel Pentium II or greater microprocessor

128 MB of RAM for Windows NT, Windows 2000, or Windows XP installations (64 MB for Windows 98 installations)

45 MB of available hard disk space

256-color SVGA graphics adapter with 800×600 resolution

a CD-ROM drive

any Windows-compatible mouse or other pointing device

Software requirements

The operating system must be one of the following:

Microsoft Windows 2000

Windows XP (with or without Service Pack 2)

Windows Server 2003 (with or without Service Pack 1)

Windows Server 2003 R2

RSLogix 500 will not run on earlier versions of Windows, nor will it run on Windows Vista.

RSLogix 500 relies on RSLinx Classic communication software, version 2.51.00 or later.

Activation

Software activation is a process by which you identify that you have installed a legitimate copy of RSLogix 500 on your computer. Activation works through an activation file that indicates to the software that you are using the software legitimately.

There are two forms of activation supported by RSLogix 500:

EVMOVE activation, uses a master disk to deliver an activation file to the system.

FactoryTalk Activation, allows to download an activation file through an Internet connection

Quick Start steps for RSLogix 500

Configure a driver in RSLinx Classic

To run the program in MicroLogix controller the computer has to be connected to the controller. Communications from RSLogix 500 take place through another software package, called RSLinx Classic. RSLogix 500 communicates to RSLinx Classic, which in turn communicates to the controller. RSLinx Classic uses drivers to connect the computer to the processor. The driver used depends on the way the processor is physically connected to the computer.

Create a new project or open an existing project

Projects are the complete set of files associated with the program logic. To create a new project, click File then New. RSLogix 500 creates a project tree for the project. The project tree gives access to program, data table, and database files. To open an existing project, click File then Open. The software displays a window that allows choosing a project to open.

Create program and data table files

The project tree helps in creating new files or accessing existing files. Program files contain controller information, the main ladder program, and any subroutine programs. Data table files contain the status information associated with external I/O and all other instructions in main and subroutine ladder program files.

Enter a logic program

Several instructions can be placed on a rung in sequence by clicking the icons one after another. RSLogix 500 places instructions from left to right. It supports a file-based editor which helps in creating and editing multiple rungs at a time.

Validate your project

Before compiling and downloading the project to a processor, validating the project is important. A single program file or entire project can be validated at one time. To verify a file, click the Verify File icon or click Edit then Verify File or Verify Project. After verification, the Verify Results output window displays and gives information about mistakes in the program. Data changes made online only affect the processor file unless the program is saved or uploaded while online to update the disk file. (Rockwell Automation, 2007)